Concentric grinding work support and method



g- 1956 'H. E. BALSIGER 2,760,312

CONCENTRIC GRINDING WORK SUPPORT AND METHOD Filed March 25, 1954 s Sheets-Sheet 1 INVENTOR I/AQOLD E.BALSIGER ATTORNEY Aug. 28, 1956 H. E. BALSIGER 2,760,312

CONCENTRIC GRINDING WORK SUPPORT AND METHOD Filed March 25, 1954 3 Sheets-Sheet 2 INVENTOR f KIROLD ELBflLS/GER sv iM ATTORNEY Aug. 28, 1956 H. E. BALSIGER 2,760,312

CONdENTRIC GRINDING WORK SUPPORT AND METHOD Filed March 25, 1954 3 Sheets-Sheet 3 I INVEN'II'OR lu/QFOLD [.BHLS/GER A ORNEY Patented Aug. 28, 1956 CONCENTRIC GRINDING WORK SUPPORT AND- NIETHOD Harold E. Balsiger, Waynesboro, Pa., assignor to Landis Tool Company, Wayneshoro, Pa.

Application March 25, 1954, Serial No. 418,574

7 Claims. (Cl. 51-103) This invention relates to a method and apparatus for grinding the outside diameter of ring-like work pieces.

In grinding some work pieces of this type it is preferred to perform the grinding operation in two steps. In the first step the work is supported at two points on the internal surface thereof as disclosed and claimed in co-pending application 280,509, filed April 4, 1952, now Patent 2,694,883, granted November 23, 1954. Rings ground on the outside diameter, while supported in this manner, have uniform wall thickness and therefore the inside and outside peripheral surfaces are concentric. This method of supporting and grinding the work insures a high degree of concentricity and, for most bearing rings, a finished diameter well within the required limits. For bearings which must be ground to closer limits, a second or finish grinding operation with the work supported on both internal and external surfaces is proposed.

It is therefore an object of this invention to provide a method of grinding ring-like work pieces which will insure both concentricity and size.

A further object of this invention is to provide a means for supporting a work piece for a grinding operation on the external peripheral surface thereof whereby required limits of accuracy will be maintained.

The means for holding size consists of a work supporting arbor similar to that disclosed in said Patent 2,694,883, except that there is only one shoe on the arbor and that in a position to provide support in a substantially vertical direction. This shoe serves to hold the work in a fixed position vertically relative to the grinding wheel. This feature is essential to obtain maximum accuracy. A second support is mounted to engage the external surface at a point substantially opposite the point of contact of the work piece with the grinding wheel.

The method consists in the use of both of these work supporting devices in succession, first to grind the external surface concentric with the internal surface, and second to grind the external surface to a predetermined diameter while supporting the work piece in the manner just disclosed for this purpose.

Figure 1 is a plan view of the grinding machine of the type on which this invention may be used.

Figure 2 is an enlarged end view showing one method of supporting the work piece.

Figure 3 is an enlarged end view showing another method of supporting the work piece.

Figure 4 is a partial end View showing means for mounting a work support of the type shown in Figure 3 on a carrier device for moving a work piece into and out of operative postion.

Numeral 10, in Figure 1, indicates a grinding wheel support which is slidably mounted on a bed (not shown). A grinding wheel 11 is rotatably mounted on a spindle 12 which is in turn supported in bearings 13 of said wheel base.

The work supporting means consists of a support 15 also slidably mounted on the same bed (not shown) as the grinding wheel support 10. A headstock 16 on said carriage has a magnetic chuck 17 mounted on the face plate 18 therefore for supporting and rotating 2. work piece 14. The means for moving the work piece into and out of operative position is substantially the same as that disclosed in said Patent 2,694,883 and consists of an arm 20 pivotally mounted at 21 on a bracket 22. Said bracket is attached to Work support 15. In said co-pending application, the supporting arm is shown in connection with a work support arbor of the type shown in Figure 2. in which the arbor 30 has peripherally spaced shoes 31 and 32 for engaging the surface of workpiece 14.

The present invention, Figures 3 and 4, includes a nonrotatable arbor 23 having a single shoe 24 for engaging the internal surface of workpiece 14. A second shoe 25 is mounted on arm 20 to support work piece 14 against the feeding thrust of the grinding wheel. The Work engaging shoe 24 may be positioned to support the work piece directly in a vertical direction, that is, at right angles to the shoe 25, or it may be slightly out of vertical position such as the upper shoe.

Operation Work piece 14 is first ground While being supported on shoes 31 and 32 of arbor 30. This method of supporting a ring-like work piece during grinding insures concentricity between the internal surface and the external surface. The work is ground in this manner until it is close to finished size. The grinding operation is continued with the work supported in the manner disclosed in Figures 3 and 4, in order to insure accuracy in size. This is accomplished by stopping the feeding movement of the grinding wheel when the space between the grinding surface thereof and the shoe 25 is equal to the desired finished size of work piece 14. The distance may be determined by feeding the wheel into contact with a workpiece ground to the desired size and by setting the feed mechanism to stop at this point.

I claim:

1. A grinding machine having a grinding wheel support and a grinding wheel rotatably mounted thereon, work driving means including a headstock, and means rotatably mounted on said headstock for engaging and rotating a workpiece, means for rotatably supporting a workpiece in operative relation with said work rotating means including an arm movable toward and from grinding position, an arbor on said arm having a work engaging shoe for engaging the inside surface of the Work and supporting same against the downward thrust of the grinding wheel, a second shoe also mounted on said arm in position to engage the external surface of said work piece at a point opposite the point of contact between said work piece and the grinding wheel.

2. The method of supporting a ring-like Work piece during a grinding operation, which consists in applying a supporting means against the internal surface thereof in a substantially vertical direction and applying a second supporting means against the external surface in a horizontal direction, applying a rotating force against the end face of said work piece and feeding a grinding Wheel against said work piece in a direction opposed to said external supporting means.

3. The method of grinding ring-like work pieces which consists in supporting the work piece at peripherally spaced points on the inside surface thereof rotating the work piece by engagement of a driving means with the end surface thereof, grinding the external peripheral surface of a work piece while so mounted to provide concentricity or uniform wall thickness and thereafter supporting said work piece vertically at one point on the inside surface thereof and at-another point on the external surface thereof, substantially opposite the point of contact between the grinding wheel and the work, and grinding the work piece to finish size while so supported.

4., In. a grinding machine for grindingtthe external surface of. ring-like workpieces, aswork support including a magnetic chuck for rotatably engaging a workpiece, a grinding wheel support, a grinding wheel rotatably mounted thereon, saidsupportubeing mounted for a feeding movement toward said workpiece, means for supporting a workpiece in operative relation withsaid chuck including an arm, a .shoe on saidrarbor for engaging the internal surface of said workpiece in a vertical plane, and means on said arm for engaging the outside surface of said workpiece in a substantially horizontal plane in oppositionto said feeding movement of .said wheel.

5. In a grinding machine for grinding the external surface of ring-like workpieces, a work support including a magnetic chuck for rotatably engaging a workpiece, a grinding wheel support, a grinding wheel rotatably mounted thereon, said support being mounted for a feeding movement toward said workpiece, means for supporting a workpiece in operative relation with said chuck including an arm, an arbor on said arm, a shoe on said arbor for. engaging the;.internal surfaceof said workpiece in vertical plane, a shoe on said arm for engaging the eX- ternal surface of said workpiece at a point substantially opposite to the point of contact between said workpiece and said grinding wheel.

6. In a grindingmachine for grinding the external surface of ring-like workpieces, a grinding wheel support, a grinding wheel rotatably mountedthereon, said support being mounted for feeding movement toward a workpiece, a work rotating means including a magnetic chuck for rotatably engaging said workpiece, means for supportingsaid workpiece in operative relation with said chuck including an arm, an arbor'on said arm, a shoe on said arbor for engaging the internal surface of said workpiece in a vertical direction and means on said arm for engaging the outside surface of said workpiece in a horizontal direction in opposition to the direction of Wheel feed.

7. A grinding machine for grinding ring-like workpieces having a grinding wheel support, a grinding wheel rotatably mounted thereon, a work driving means for rotating a workpiece through the end face thereof, means for rotatably supporting said workpiece in operative relation with said grinding wheel and said Work driving means including an arm movable transversely toward and from said grinding Wheel, said arm having a work engaging shoe mounted thereon for engaging the inside surface of a workpiece in position for supporting said workpiece against gravity, and a second shoe on said arm mounted in position to engage the external surface of said workpiece at a point substantially opposite the point of contact between the workpiece and the grinding wheel.

References Cited in the file ofthis patent UNITED STATES PATENTS 1,772,932 Einstein Aug. 12, 1930 1,814,367 Caster July 14, 1931 1,904,045 Haas Apr. 18, 1933 1,948,392 Ogilvie Feb. 20, 1934 2,032,269 Einstein Feb. 25, 1936 2,059,723 Briney Nov. 3, 1936 2,243,371 Blood May 27, 1941 2,478,607 Theler Aug. 9, 1949 2,635,395 Arms Apr. 21, 1953 2,646,652 Blood July 28, 1953 2,694,883 Balsiger Nov. 23, 1954 FOREIGN PATENTS 122,671 Great Britain Dec. 27, 1917 

